Randomization is used extensively in the field of gambling. Imperfect randomization may allow a skilled gambler to have an advantage, so much research has been devoted to effective randomization. A classic example of randomization is shuffling playing cards.

Randomization is not haphazard; it serves a purpose in both frequentist and Bayesian statistics. A frequentist would say that randomization reduces bias by equalising other factors that have not been explictly accounted for in the experimental design. Considerations of bias are of little concern to Bayesians, who recommend randomization because it produces ignorable designs. In design of experiments, frequentists prefer Completely Randomized Designs. Other experimental designs are used when a full randomization is not possible. These cases include experiments that involve blocking and experiments that have hard-to-change factors.